1 files changed, 29 insertions, 31 deletions

diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index 691fa98a18c4..1e96c4df7061 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -33,11 +33,10 @@
 /* do_async_xor - dma map the pages and perform the xor with an engine */
 static __async_inline struct dma_async_tx_descriptor *
 do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
-             unsigned int offset, int src_cnt, size_t len,
+             unsigned int offset, int src_cnt, size_t len, dma_addr_t *dma_src,
              struct async_submit_ctl *submit)
 {
         struct dma_device *dma = chan->device;
-        dma_addr_t *dma_src = (dma_addr_t *) src_list;
         struct dma_async_tx_descriptor *tx = NULL;
         int src_off = 0;
         int i;
@@ -125,9 +124,14 @@ do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
         int xor_src_cnt;
         int src_off = 0;
         void *dest_buf;
-        void **srcs = (void **) src_list;
+        void **srcs;
 
-        /* reuse the 'src_list' array to convert to buffer pointers */
+        if (submit->scribble)
+                srcs = submit->scribble;
+        else
+                srcs = (void **) src_list;
+
+        /* convert to buffer pointers */
         for (i = 0; i < src_cnt; i++)
                 srcs[i] = page_address(src_list[i]) + offset;
 
@@ -178,17 +182,26 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
         struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR,
                                                       &dest, 1, src_list,
                                                       src_cnt, len);
+        dma_addr_t *dma_src = NULL;
+
         BUG_ON(src_cnt <= 1);
 
-        if (chan) {
+        if (submit->scribble)
+                dma_src = submit->scribble;
+        else if (sizeof(dma_addr_t) <= sizeof(struct page *))
+                dma_src = (dma_addr_t *) src_list;
+
+        if (dma_src && chan) {
                 /* run the xor asynchronously */
                 pr_debug("%s (async): len: %zu\n", __func__, len);
 
                 return do_async_xor(chan, dest, src_list, offset, src_cnt, len,
-                                    submit);
+                                    dma_src, submit);
         } else {
                 /* run the xor synchronously */
                 pr_debug("%s (sync): len: %zu\n", __func__, len);
+                WARN_ONCE(chan, "%s: no space for dma address conversion\n",
+                          __func__);
 
                 /* in the sync case the dest is an implied source
                  * (assumes the dest is the first source)
@@ -241,11 +254,16 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
                                                       src_cnt, len);
         struct dma_device *device = chan ? chan->device : NULL;
         struct dma_async_tx_descriptor *tx = NULL;
+        dma_addr_t *dma_src = NULL;
 
         BUG_ON(src_cnt <= 1);
 
-        if (device && src_cnt <= device->max_xor) {
-                dma_addr_t *dma_src = (dma_addr_t *) src_list;
+        if (submit->scribble)
+                dma_src = submit->scribble;
+        else if (sizeof(dma_addr_t) <= sizeof(struct page *))
+                dma_src = (dma_addr_t *) src_list;
+
+        if (dma_src && device && src_cnt <= device->max_xor) {
                 unsigned long dma_prep_flags;
                 int i;
 
@@ -275,6 +293,9 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
                 enum async_tx_flags flags_orig = submit->flags;
 
                 pr_debug("%s: (sync) len: %zu\n", __func__, len);
+                WARN_ONCE(device && src_cnt <= device->max_xor,
+                          "%s: no space for dma address conversion\n",
+                          __func__);
 
                 submit->flags |= ASYNC_TX_XOR_DROP_DST;
                 submit->flags &= ~ASYNC_TX_ACK;
@@ -293,29 +314,6 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
 }
 EXPORT_SYMBOL_GPL(async_xor_val);
 
-static int __init async_xor_init(void)
-{
-        #ifdef CONFIG_DMA_ENGINE
-        /* To conserve stack space the input src_list (array of page pointers)
-         * is reused to hold the array of dma addresses passed to the driver.
-         * This conversion is only possible when dma_addr_t is less than the
-         * the size of a pointer.  HIGHMEM64G is known to violate this
-         * assumption.
-         */
-        BUILD_BUG_ON(sizeof(dma_addr_t) > sizeof(struct page *));
-        #endif
-
-        return 0;
-}
-
-static void __exit async_xor_exit(void)
-{
-        do { } while (0);
-}
-
-module_init(async_xor_init);
-module_exit(async_xor_exit);
-
 MODULE_AUTHOR("Intel Corporation");
 MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
 MODULE_LICENSE("GPL");